Programs for modding please?

First off, what programs do you use to make custom units? As in take parts from other units and implement them on the said unit you want to customize?
Second, what program(s) do you use to re-colour or re-make the UV map for models? Because I'm making custom outfits for my PDF/PDF2nd/PDX models and I need to know how to make UV maps from scratch.
Replies
If you want to edit the texture/color, yes you'll need image editing program
like Photoshop
or Gimp, tho some ppl said Gimp is too confusing